There were several versions of the EMIT diaphragms each with different frequency responses. The EMITs he has pictured are different from the ones used in the IRS V's. I still have a few dozen new ones left from when Harmon was closing them out but the best engineer that I have found for repairs is Cory Johnson. His contact information is here on the site for AA members to access. Cory's work was checked by Arnie Nudell, the original designer, who said the system with his drivers was the best IRS V that he had ever heard. The system is in Paul McGowen's music room one at PS Audio as of this writing. The EMIT-K's used in the IRS V were the best version. In fact, Infinity used to sell an upgrade kit to convert older systems to the EMIT-K's.